CVE-2026-40706

Description

In NTFS-3G 2022.10.3 before 2026.2.25, a heap buffer overflow exists in ntfs_build_permissions_posix() in acls.c that allows an attacker to corrupt heap memory in the SUID-root ntfs-3g binary by crafting a malicious NTFS image. The overflow is triggered on the READ path (stat, readdir, open) when processing a security descriptor with multiple ACCESS_DENIED ACEs containing WRITE_OWNER from distinct group SIDs.